Page 87 - Physico-Chemical Niche Conditions for Bone Cells

MATERIALS AND METHODS Experimental setup
A schematic diagram of the experimental setup is shown in Fig. 1A.
Figure 1. Schematic diagram of the experimental setup. (A) Fluid dynamics (fluid velocity, fluid pressure, and fluid shear stress) over a bone cell as a result of PFF was modeled during 5 s (immediate impact: grey area). NO production as a result of 1 h ± PFF was measured (initial down-stream impact: grey and dark red area). Metabolic activity, cell morphology and orientation, and gene expression were assessed after 0, 1, 3, and 6 h post-incubation (short-term down-stream impact: light blue area). Collagen protein production were assessed after 21 days (long-term down-stream impact: light green area). ECM mineralization was determined after 28 days (long-term down-stream impact: purple area). (B) Schematic illustration of a parallel-plate flow chamber measuring 24×24×0.15 mm (length×width×height; total volume, 86.4 mm3) used to simulate fluid velocity, fluid pressure, and fluid shear stress, over a
-5 3
bone cell (total volume, 1.2×10 mm ; length, 83 μm; height, 7 μm) used in the experimental study. (C)
Simulation volume, mesh, and boundary conditions (inlet flow rate, outlet zero static pressure, no wall slip) applied in the FE modeling. Dark red arrows: 1 h ± PFF; light blue arrows: post-incubation; green/purple arrows: 21/28 days of culture in osteogenic medium.
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